Researchers also noted the amount of bedding used and found that 50% of the herds used more than 2 centimeters of bedding while the other half used less than 2 centimeters.

Study Results

1. The herd lying time averaged 12.4 hours per day for all 100 herds. 56% of the cows had hock injuries and 43% had knee injuries.
2. Farms using mattresses had an increased average herd lying time of 96 minutes per day than farms using rubber mats. 
3. The farms using mattresses had 13% fewer cows with hock injuries and 20% fewer with knee injuries than farms using rubber mats.
4. Farms using 2 centimeters or more of bedding on mattresses had an increased average herd lying time of 72 minutes per day than farms using less than 2 centimeters on rubber mats. 
5. Farms using 2 centimeters or more of bedding on mattresses had 24% fewer hock injuries and 25% fewer knee injuries than farms using less than 2 centimeters on rubber mats.

Conclusions
Although there is still much more research to be done on determining the best options for cow stall base and bedding materials, researchers identified several factors that can make a difference with cow comfort. First, stall bases made from cushion-like materials are the most comfortable. However, bases should not be too soft (can deteriorate quickly) or too hard (can be uncomfortable and slippery). Second, bedding is important for cushioning, absorbing moisture, and reducing friction between a cow and the base. Bases should be kept clean and bedding should be replaced when it becomes soiled or wet.

Source: Harold K. House, “Comfort and Stability”, MilkProducer, March 2013: 44, 46.